Long-term clinical observation of patients with heterozygous KIF1A variants.

KIF1A-related disorders (KRDs) encompass recessive and dominant variants with wide clinical variability. Recent genetic investigations have expanded the clinical phenotypes of heterozygous KIF1A variants. However, there have been a few long-term observational studies of patients with heterozygous KIF1A variants. A retrospective chart review of consecutive patients diagnosed with spastic paraplegia at Miyagi Children's Hospital from 2016 to 2020 identified six patients with heterozygous KIF1A variants. To understand the long-term changes in clinical symptoms, we examined these patients in terms of their characteristics, clinical symptoms, results of electrophysiological and neuroimaging studies, and genetic testing. The median follow-up period was 30 years (4-44 years). This long-term observational study showed that early developmental delay and equinus gait, or unsteady gait, are the first signs of disease onset, appearing with the commencement of independent walking. In addition, later age-related progression was observed in spastic paraplegia, and the appearance of axonal neuropathy and reduced visual acuity were characteristic features of the late disease phenotype. Brain imaging showed age-related progression of cerebellar atrophy and the appearance of hyperintensity of optic radiation on T2WI and FLAIR imaging. Long-term follow-up revealed a pattern of steady progression and a variety of clinical symptoms, including spastic paraplegia, peripheral neuropathy, reduced visual acuity, and some degree of cerebellar ataxia. Clinical variability between patients was observed to some extent, and therefore, further studies are required to determine the phenotype-genotype correlation.

The Clinical Course and Treatment of a Case of Refractory Systemic Juvenile Myasthenia Gravis Successfully Treated with Thymectomy.

Juvenile myasthenia gravis (JMG) exhibits a more favorable response to glucocorticoids and has a better prognosis than adult myasthenia gravis. However, no established treatment exists for refractory JMG. Although thymectomy has been performed in several patients with refractory systemic JMG, there are few detailed clinical descriptions of patients who underwent thymectomy. Here, we present the case of a 10-year-old boy with refractory systemic JMG who was successfully treated with thymectomy. The patient developed symptoms, including dysphagia, malaise, diurnal ptosis, and weakness in the trunk muscles, and he was diagnosed with generalized JMG. Despite undergoing various treatments, including steroids, tacrolimus, steroid pulse therapy, intravenous immunoglobulin, azathioprine (AZT), and rituximab, his symptoms did not improve. Therefore, he underwent a thoracoscopic thymectomy 24 months after disease onset. Thymectomy led to remission, as demonstrated by a significant reduction in the quantitative myasthenia gravis score and anti-acetylcholine receptor antibody levels, which persisted for 43 months after surgery. Our case demonstrates the effectiveness of thymectomy in systemic JMG patients with positive anti-acetylcholine receptor antibodies, despite therapeutic failure with AZT and rituximab, within 2 years of disease onset.

Treatment of ZC4H2 Variant-Associated Spastic Paraplegia with Selective Dorsal Rhizotomy and Intensive Postoperative Rehabilitation: A Case Report.

Selective dorsal rhizotomy (SDR) has been used to treat children with spastic cerebral palsy (CP), and its beneficial effect on quality of life and ambulation has been confirmed in long-term follow-up studies. However, the role of SDR in the treatment of spasticity in patients with hereditary spastic paraplegia (HSP) and related disorders is not well-established. Here, we report the first patient with the ZC4H2 variant who underwent SDR to treat spastic paraplegia. Abnormal gait was discovered during a regular checkup at the age of 3 years and 9 months, and she was diagnosed with spastic paraplegia. She was heterozygous for the ZC4H2 variant and underwent SDR at the age of 5 years and 11 months, which alleviated the spasticity. The patient underwent inpatient postoperative rehabilitation for 4 months and continued outpatient physiotherapy after discharge. The Gross Motor Function Measure-88 score and maximum walking speed decreased transiently 1 month postoperatively, but gradually recovered, and continuously improved 6 months postoperatively. SDR and postoperative intensive rehabilitation were effective in improving motor and walking functions up to 6 months after surgery, although long-term follow-up is needed to draw conclusions.

Multiple Cerebral Hemorrhages and White Matter Lesions Developing after Severe hMPV Pneumonia in a Patient with Trisomy 13: A Case Report and Review of the Literature.

Human metapneumovirus (hMPV) is a common cause of upper and lower respiratory tract infections in children. A few case reports have described hMPV encephalitis or encephalopathy. Neuroimaging data on patients with hMPV encephalitis are scarce. We report a patient with trisomy 13 who developed severe hMPV pneumonia, multifocal cerebral and cerebellar hemorrhagic infarctions and extensive cerebral white matter demyelination. Although adult respiratory distress syndrome and disseminated intravascular coagulation contributed to the devastating central nervous system (CNS) lesions, endothelial dysfunction of the CNS caused by hMPV infection probably also played a pathophysiological role in this case.

Two Siblings with Cerebellar Ataxia, Mental Retardation, and Disequilibrium Syndrome 4 and a Novel Variant of ATP8A2.

Cerebellar ataxia, mental retardation, and disequilibrium syndrome 4 (CAMRQ4) is early onset neuromotor disorder and intellectual disabilities caused by variants of ATP8A2. We report sibling cases and systematically analyze previous literature to increase our understanding of CAMRQ4. Japanese siblings presented with athetotic movements at 1 and 2 months of age. They also had ptosis, ophthalmoplegia, feeding difficulty, hypotonia, and severely delayed development. One patient had retinal degeneration and optic atrophy. Flattening of the auditory brainstem responses and areflexia developed. At the last follow-up, neither patient could sit or achieve head control, although some nonverbal communication was preserved. Whole exome sequencing revealed compound heterozygous variants of ATP8A2: NM_016529.6:c.[1741C>T];[2158C>T] p.[(Arg581*)];[(Arg720*)]. The p.(Arg581*) variant has been reported, while the variant p.(Arg720*) was novel. The symptoms did not progress in the early period of development, which makes it difficult to distinguish from dyskinetic cerebral palsy, particularly in solitary cases. However, visual and hearing impairments associated with involuntary movements and severe developmental delay may be a clue to suspect CAMRQ4.

A novel homozygous mutation of the TFG gene in a patient with early onset spastic paraplegia and later onset sensorimotor polyneuropathy.

The tropomyosin-receptor kinase fused gene (TFG) has recently been implicated in several distinct hereditary disorders, including the autosomal-recessive form of complicated hereditary spastic paraplegia called SPG57. Previously, three homozygous variants of the TFG gene were reported in five families with SPG57, in which early onset spastic paraplegia, optic atrophy, and peripheral neuropathy were variably identified. Here, we present the first Japanese patient with SPG57, and have added a homozygous p.Ile66Thr variant as the fourth SPG57 genotype.

Leucine-485 deletion variant of BRAF may exhibit the severe end of the clinical spectrum of CFC syndrome.

The genotype-phenotype correlation in BRAF variant in cardio-facio-cutaneous (CFC) syndrome is not clearly defined. Here we report a case with a severe clinical phenotype and a novel BRAF variant, p.Leu485del. The present case showed severe intellectual disability, impaired awareness, hyperekplexia, involuntary movements, early onset refractory seizures, and delayed myelination on brain magnetic resonance imaging as well as a polycystic and dysplastic kidney, which are previously unreported anomalies in CFC or RAS/mitogen-activated protein kinase syndromes related to BRAF variant. CFC syndrome, especially caused by BRAF variant, should be included in the differential diagnosis of patients with developmental and epileptic encephalopathies and hyperekplexia. Furthermore, we need to keep in mind that missense variants or the deletion of Leucine-485 may be associated with severe symptoms.

A case of new PCDH12 gene variants presented as dyskinetic cerebral palsy with epilepsy.

Here we report a Japanese patient with new compound heterozygous truncating variants in the PCDH12 gene. As compared to the previously reported families who had congenital microcephaly, intrauterine growth retardation, intracranial calcification, and neonatal seizure associated with dysplasia of the midbrain-hypothalamus-optic tract, the present patient showed no midbrain-hypothalamus dysplasia or congenital/postnatal microcephaly, but dyskinetic cerebral palsy and severe intellectual disability as well as multifocal epilepsy. To understand phenotypic spectrum associated with PCDH12 variants, more reports are needed.

A novel mutation in the proteolytic domain of LONP1 causes atypical CODAS syndrome.

Cerebral, ocular, dental, auricular, skeletal (CODAS) syndrome is a rare autosomal recessive multisystem disorder caused by mutations in LONP1. It is characterized by intellectual disability, cataracts, delayed tooth eruption, malformed auricles and skeletal abnormalities. We performed whole-exome sequencing on a 12-year-old Japanese male with severe intellectual disability, congenital bilateral cataracts, spasticity, hypotonia with motor regression and progressive cerebellar atrophy with hyperintensity of the cerebellar cortex on T2-weighted images. We detected compound heterozygous mutation in LONP1. One allele contained a paternally inherited frameshift mutation (p.Ser100Glnfs*46). The other allele contained a maternally inherited missense mutation (p.Arg786Trp), which was predicted to be pathogenic by web-based prediction tools. The two mutations were not found in Exome Variant Server or our 575 in-house control exomes. Some features were not consistent with CODAS syndrome but overlapped with Marinesco-Sjögren syndrome, a multisystem disorder caused by a mutation in SIL1. An atypical mutation site may result in atypical presentation of the LONP1 mutation.

Patchy white matter hyperintensity in ring chromosome 18 syndrome.

Ring chromosome 18 syndrome is a chromosomal abnormality in which partial deletions occur at both ends of chromosome 18, that is, distally on the short and long arms. Previously reported brain magnetic resonance imaging (MRI) abnormalities include diffuse hyperintensity in the white matter, which has been regarded as hypomyelination because the gene for myelin basic protein production is located on the long arm of chromosome 18. We report the case of a 14-year-old boy with ring chromosome 18 syndrome, whose MRI showed patchy asymmetrical T2 and fluid-attenuated inversion-recovery hyperintensities in the deep white matter as well as diffuse hypomyelination. These patchy lesions may indicate demyelination or gliosis rather than hypomyelination. This result differs from previous reports.

Xq26.1-26.2 gain identified on array comparative genomic hybridization in bilateral periventricular nodular heterotopia with overlying polymicrogyria.

Periventricular nodular heterotopia (PNH) with overlying polymicrogyria (PMG) is a recently described, developmental brain malformation; however, the causative genes of this malformation have not yet been identified. We report on a 5-year-old Japanese male with bilateral PNH with overlying PMG. He had mild intellectual disability, distinctive facial features, short stature, and microcephaly, with cardiac disorders. No mutation was identified in Sanger sequences for FLNA and ARFGEF2; however, array comparative genomic hybridization revealed an approximately 0.8Mb gain at Xq26.1-26.2, which included three genes: IGSF1, OR13H1, and FIRRE. We identified the same 3-copy gain in his mother; despite identifying the same abnormality in the mother, it must still be considered as a possible cause for the abnormalities, as X-inactivation in the mother could have led to her not expressing the same phenotype. This case may provide important clues for identifying the genes responsible and help in the understanding of the pathogenesis of this disorder.

Brain magnetic resonance imaging and motor and intellectual functioning in 86 patients born at term with spastic diplegia.

AIM: To investigate the association between magnetic resonance imaging (MRI) patterns and motor function, epileptic episodes, and IQ or developmental quotient in patients born at term with spastic diplegia. METHOD: Eighty-six patients born at term with cerebral palsy (CP) and spastic diplegia (54 males, 32 females; median age 20 y, range 7-42 y) among 829 patients with CP underwent brain MRI between 1990 and 2008. The MRI and clinical findings were analysed retrospectively. Intellectual disability was classified according to the Enjoji developmental test or the Wechsler Intelligence Scale for Children (3rd edition). RESULTS: The median ages at diagnosis of CP, assignment of Gross Motor Function Classification System (GMFCS) level, cognitive assessment, and MRI were 2 years (range 5 mo-8 y), 6 years (2 y 8 mo-19 y), 6 years (1 y 4 mo-19 y), and 7 years (10 mo-30 y) respectively. MRI included normal findings (41.9%), periventricular leukomalacia, hypomyelination, and porencephaly/periventricular venous infarction. The frequency of patients in GMFCS levels III to V and intellectual disability did not differ between those with normal and abnormal MRI findings. Patients with normal MRI findings had significantly fewer epileptic episodes than those with abnormal ones (p=0.001). INTERPRETATION: Varied MRI findings, as well as the presence of severe motor dysfunction and intellectual disability (despite normal MRI), suggest that patients born at term with spastic diplegia had heterogeneous and unidentified pathophysiology.

Neonatal developmental and epileptic encephalopathy with movement disorders and arthrogryposis: A case report with a novel missense variant of SCN1A.

Variants of SCN1A represent the archetypal channelopathy associated with several epilepsy syndromes. The clinical phenotypes have recently expanded from Dravet syndrome. CASE REPORT: We present a female patient with the de novo SCN1A missense variant, c.5340G > A (p. Met1780Ile). The patient had various clinical features with neonatal onset SCN1A epileptic encephalopathy, arthrogryposis multiplex congenita, thoracic hypoplasia, thoracic scoliosis, and hyperekplexia. CONCLUSION: Our findings are compatible with neonatal developmental and epileptic encephalopathy with movement disorders and arthrogryposis; the most severe phenotype probably caused by gain-of-function variant of SCN1A. The efficacy of sodium channel blocker was also discussed. Further exploration of the phenotype-genotype relationship of SCN1A variants may lead to better pharmacological treatments and family guidance.

A first case of childhood chronic inflammatory demyelinating polyneuropathy associated with alopecia universalis.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired demyelinating disease of the peripheral nervous system with unknown etiology. Alopecia universalis, an advanced form of alopecia areata (AA), is a condition characterized by complete hair loss. Here we report the first case of childhood CIDP associated with AA who was successfully treated with a combination of intravenous immunoglobulin (IVIg) and corticosteroids. CASE REPORT: This case describes a nine-year-old Japanese girl who developed alopecia, progressive muscle weakness, and eventually loss of walking ability (at ages 2, 4, and 7, respectively). She was treated with IVIg and prednisolone combination therapy, which improved muscle weakness and alopecia. She was positive for serum IgG-GM2 type anti-glycolipid antibodies, which may be associated with this rare combination of diseases.

Intravenous ketogenic diet therapy for neonatal-onset pyruvate dehydrogenase complex deficiency.

BACKGROUND: Pyruvate dehydrogenase complex (PDHC) deficiency is an inborn error of metabolism that causes lactic acidosis and neurodevelopmental changes. Five causative genes have been identified: PDHA1, PDHB, DLAT, DLD, and PDHX. Four neurological phenotypes have been reported: neonatal encephalopathy with lactic acidosis, non-progressive infantile encephalopathy, Leigh syndrome, and relapsing ataxia. Of these, neonatal encephalopathy has the worst mortality and morbidity and there is no effective treatment. SUBJECTS AND METHODS: We studied two girls who were clinically diagnosed with PDHC deficiency as neonates; they were subsequently found to have PDHA1 mutations. The clinical diagnosis was based on white matter loss and a lateral ventricular septum on fetal MRI, spasticity of the lower extremities, and lactic acidosis worsening after birth. Intravenous ketogenic diets were started within 24 h after birth. The ketogenic ratio was increased until the blood lactate level was controlled, while monitoring for side effects. RESULTS: In both cases, the lactic acidosis improved immediately with no apparent side effects. Both children had better developmental outcomes than previously reported cases; neither exhibited epilepsy. CONCLUSIONS: Intravenous ketogenic diet therapy is a treatment option for neonatal-onset PDHC deficiency. Further studies are needed to optimize this therapy.

A patient with early-onset SMAX3 and a novel variant of ATP7A.

OBJECTIVE: To describe clinical and genetic studies on a patient with early-onset spinal muscular atrophyX3 (SMAX3) with novel variant of ATP7A. METHODS: Clinical, neurophysiological, neuroimaging and pathological examinations were performed. Whole exome sequencing was applied to search genetic bases of this patient. RESULTS: The patient had gait abnormality from early infantile period. Muscle imaging at 42 years old showed predominant involvement of proximal muscles as compared to the distal muscles. The patient had a novel variant of ATP7A, which was the fourth genotype of ATP7A exhibited as SMAX3. Contrary to previous reports of distal motor neuropathy, the clinical and neuroimaging findings in this case revealed dominant involvement in the proximal portion of the extremities and trunk, which is similar to patients with type III SMA. CONCLUSION: The dominant involvement of proximal motor system in this patient may expand the phenotypic variability of SMAX3. We need to be aware of this disorder in differential diagnosis of patients with type III SMA-like phenotype.

A novel stop-gain CUL3 mutation in a Japanese patient with autism spectrum disorder.

BACKGROUND: CUL3 encodes cullin-3, a core component of a ubiquitin E3 ligase. CUL3 mutations have recently been associated with autism spectrum disorder (ASD); however, the detailed clinical courses have been described in only a limited number of patients with CUL3 mutations and neurodevelopmental diseases, including ASD. CASE REPORT: A 21-month-old Japanese girl presented with febrile status epilepticus and thereafter exhibited developmental regression, including loss of her verbal ability, eye contact, and skills in activities of daily living. Trio-based exome sequencing identified a de novo two-base insertion in CUL3, c.1758_1759insTG, p.(Thr587*). CONCLUSION: We report a case of a patient with ASD and a stop-gain CUL3 variant. Screening of CUL3 variants is worth considering for patients with ASD, especially those with Rett-like developmental regression.

Reduced efficacy of perampanel in patients with severe motor and intellectual disabilities syndrome and drug-resistant epilepsy: A single-center analysis from Japan.

People with severe motor and intellectual disabilities syndrome (SMIDS) have multiple comorbidities and high mortality rates. This study examined whether there is a difference in the efficacy and tolerability of perampanel (PER) between patients with drug-resistant epilepsy with or without SMIDS. The study identified 65 patients with drug-resistant epilepsy who underwent PER treatment as adjunctive therapy. The 50 % responder rate was 22 % (14/65) overall and 11 % (5/44) in patients with SMIDS versus 43 % (9/21) in patients without SMIDS (p <0.01). Although the overall 50 % responder rate was similar to those of previous reports, PER was less efficacious in the patients with SMIDS; nevertheless, PER was tolerated in the patients with SMIDS.

Two cases of persistent falcine and occipital sinuses.

BACKGROUND: The coexistence of falcine and occipital sinuses is rare and its natural course has not been reported. CASE REPORTS: Two patients with persistent falcine and occipital sinuses are described. Both patients had straight sinuses. In one, both the transverse and sigmoid sinuses were hypoplastic and the patient had an acquired Chiari I malformation. The other patient had no other venous anomalies and had a normal posterior cranial fossa. CONCLUSION: The coexistence of falcine and occipital sinuses can lead to an acquired Chiari I malformation. These cases suggest the importance of checking other venous and brain anomalies in this situation.